Working as a caregiver, the Camarillo resident and single mother of two grown children resigned herself to a reclusive life.

"God was watching over me, I think," DeRosa said. "He saw how miserable I was going to be."

She made an appointment with Dr. Hooman Zarrinkelk, a Ventura oral and maxillofacial surgeon who performs a procedure called All-on-Four, an implant method that provides permanent, nonremovable teeth in one day.

"Basically, we're providing a simple and quick solution for people with failing dentition or no teeth. We can usually do it in one appointment, and it's virtually painless," said Zarrinkelk, who works in tandem with Dr. Saj Jivraj, a prosthodontist in Oxnard.

"When the body loses teeth, after a while, it starts to absorb away the bone, and so there's no bone to support the denture," Zarrinkelk said. "That causes pain and loss of anchorage for the denture."

The original solution of bone grafting was far more painful, time-consuming and costly, Zarrinkelk said.

"We have to operate and remove a portion of either hip or rib bone, transplant it to the jaw and then wait for the bone to graft," he said. "I did a lot of these surgeries. It was the standard of care, and it could take up to two years before the teeth would grow or become permanent."

The All-on-Four method uses 3-D scanning to find the existing bone and place implants made by Nobel Biocare.

"We use 3-D CT scans to find bone and angle the implant, sort of like when you put a nail in a wall to hang a picture," Jivraj said. "If you angle it, the picture will hang better. It's a similar concept here."

One patient had implants that were placed into a cheekbone, as it was the only one left after years of bone loss.

"The patient had no pain," Jivraj said.

Dr. James Jacobs, an oral surgeon who works with Zarrinkelk, said: "There's no incision, just drilling, and we can even do it on the computer first, using the 3-D scans, creating a virtual surgery so we know exactly where we're going."

The procedure costs about $50,000, but that is less than half of what it cost several years ago. Many dental plans and some medical insurance plans will pay for it, according to Zarrinkelk.

"This is a quality-of-life issue for people. The cost of not doing something is far greater to most people," Jivraj said.

Once the implants are placed at Zarrinkelk's office, the patient goes to Jivraj's office to have the new teeth put in. A metal bar designed from another 3-D scan is milled to fit the patient exactly, Jivraj said.

"Ninety-nine percent of patients who have this kind of bone loss — we can treat them immediately, and the teeth don't come out, and there's no or very little pain," Zarrinkelk said.

The procedure was developed by Dr. Paulo Malo in Portugal, and Zarrinkelk and Jivraj have traveled there to train with him. Now, the two hold seminars on the procedure for dentists and oral surgeons. Zarrinkelk will do a procedure on stage in New York next month as dental professionals watch.

"The World Health Organization estimates that the population without teeth will double to 84 million people in North America in the next few years," Zarrinkelk said. "But most dentists don't know that this is available to everybody and can work for them."

DeRosa said her life has changed.

"I got job interviews and a new job after the procedure," she said. "It's wonderful. I'm not embarrassed anymore."